About Sum Cross

Sum Cross is a six-by-six arithmetic crossword. Instead of letters, you get runs of white squares and a target total for each one: fill the run with digits from one to nine that add to that total, never repeating a digit inside the same run. Each white square must satisfy both its across and down run.

Each daily board is checked for one solution. Arithmetic stays light; the work is in the crossing, not the adding.

For a three-cell run totalling 7, the no-repeat candidates are the digits 1, 2 and 4. The crossing clues still decide which of those digits belongs in each square, so do not treat the set as an ordered answer.

Strategy tips

Learn the forced runs. Two squares totalling 3 can only be 1 and 2; totalling 17 can only be 8 and 9. Three squares totalling 6 must be 1, 2 and 3.
The extremes are your entry points. Very low and very high totals have the fewest arrangements, so start there and let them constrain their crossings.
Work a crossing, not a run. Once you know a run is some arrangement of 1, 2 and 3, the down clue through one of those squares usually eliminates two of the three possibilities immediately.
Sum the whole line when you are stuck. If a run of three needs 20 and you have placed a 3, the other two must make 17, which is only 8 and 9.
A wall resets repetition: the same digit may appear in separate runs.

Controls

Click or tap a white square and type a digit from 1 to 9. Use Check to highlight any digit that does not match the solution.

For visual line deduction, try the Nonogram next. For a binary puzzle where every row and column must balance its 0s and 1s, try Binairo.